Affinity chromatography can be used to purify proteins such as growth factor receptors. The ligand of the growth factor receptor can be linked to resin, and then an extract containing membrane proteins can be poured over the resin. If a high concentration of free ligand were poured over the resin next, what would you expect to happen?
If a high concentration of free ligand were poured over the resin next, the growth-factor receptor will be released from the resin since the excess ligand competes with ligand attached to the resin.